18215620 has 12 divisors (see below), whose sum is σ = 38252844. Its totient is φ = 7286240.

The previous prime is 18215597. The next prime is 18215629. The reversal of 18215620 is 2651281.

It can be written as a sum of positive squares in 2 ways, for example, as 13089924 + 5125696 = 3618^2 + 2264^2 .

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (18215629) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 455371 + ... + 455410.

It is an arithmetic number, because the mean of its divisors is an integer number (3187737).

Almost surely, 2^18215620 is an apocalyptic number.

18215620 is a gapful number since it is divisible by the number (10) formed by its first and last digit.

It is an amenable number.

18215620 is an abundant number, since it is smaller than the sum of its proper divisors (20037224).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

18215620 is a wasteful number, since it uses less digits than its factorization.

18215620 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 910790 (or 910788 counting only the distinct ones).

The product of its (nonzero) digits is 960, while the sum is 25.

The square root of 18215620 is about 4267.9761011515. The cubic root of 18215620 is about 263.1164408949.

The spelling of 18215620 in words is "eighteen million, two hundred fifteen thousand, six hundred twenty".